This article is an extract from the Wiley title: Digital Macro & Close-Up Photography For Dummies by Thomas Clark. For more information on this book and other Wiley titles, visit Wiley's website.
Similar to lines, tonal contrast (the difference between the dark and light areas in a photograph) can guide viewers through a frame. The first place a person looks in a photograph is the point where the greatest level of contrast exists.
Photo by Pete.
In most cases you want your subject to exist at the point of highest contrast. That way you can assure that your viewers look at the subject and subconsciously see it as being important. You can also ensure that your viewer's eyes are pulled toward the subject as they move into other areas of the frame (especially the edges). A successful composition causes people to view the entire frame, coming back to the point of interest (the subject) multiple times.
The edges of your frame represent a threat, as they are the natural exiting point for viewers. In order to keep people's eyes from wandering out of the frame, photographers often darken the edges of their frames, or compose images in such a way so the edges are covered in shadow.
By making your edges the darkest area of your frame, you attempt to draw the viewer back to the lighter areas within the frame.
To darken the edges of your frame, try:
- Using the vignette tool, available in most photo-editing software.
- Place a vignette filter in front of your lens. You can make one by darkening the edges of a UV filter with a marker or spray-paint, or by cutting a whole (slightly smaller than your lens) in a black piece of foam core and positioning it in front of your lens while shooting. The farther you hold the foam core from your lens, the more apparent the vignette will become in your image.
- Using black flags to cast shadows into your scene, affecting the specific areas that make up the edges of your frame.